1. Field of the Invention
The present invention relates to a multi-way flipping switch applicable to an automotive mirror driving device or the like and adapted to output an electric signal corresponding to a direction of inclination of an operating member.
2. Description of the Related Art
Japanese Utility Model Laid-Open No. 59-188644 discloses a conventional example of such a multi-way flipping switch, which comprises an operating member held so as to be capable of being inclined in a number of directions, a base plate having a plurality of stationary contacts, a click rubber member in the form of a sheet having a plurality of hollow protrusions each containing a movable contact, a driving member arranged between the operating member and the base plate and adapted to transmit an inclining force for the operating member to the above-mentioned hollow protrusions, and a spring for restoring the operating member and the driving member to a neutral position. In this conventional multi-way flipping switch, when the operating member is inclined in an arbitrary direction against the resilient force of the spring, the hollow protrusion of the click rubber member positioned in the direction of inclination is pressed by the driving member to generate a click feel and, at the same time, the movable contact provided in this hollow protrusion is brought into contact with the stationary contact arranged opposite thereto, whereby an electric signal corresponding to the direction of inclination can be output. When the operating force causing the inclination of the operating member is cancelled, the driving member and the operating member are restored to the neutral position by the resilient force of the spring and, at the same time, the hollow protrusion is restored to the non-operating state by its own resilient force, with the result that the movable contact is separated from the stationary contact and returns to the original position, which corresponds to the OFF state.
Japanese Utility Model Publication No. 3-23639 discloses another example of conventional multi-way flipping switch, which comprises an operating member, a base plate having a plurality of stationary contacts, and a sheet-shaped click rubber member having a plurality of hollow protrusions each containing a movable contact, wherein the operating member is provided with a longer projection and a plurality of shorter projections positioned around the longer projection, with the lower surface of the projections respectively abutting the hollow protrusions of the click rubber member. In this multi-way flipping switch, when the operating member is inclined in an arbitrary direction, the hollow protrusion positioned in the direction of inclination is pressed by the corresponding projection. The top end surface of each hollow protrusion is formed as an inclined surface descending toward the center, so that the top end section of the hollow protrusion is parallel to the surface of the base plate when the operating member is inclined. As a result, the movable contact inside the hollow protrusion is reliably brought into contact with the associated stationary contact, thereby providing a satisfactory contact state. Further, when the operating member is inclined by a predetermined angle, a part of the lower end section of the protrusion is passed through a through-hole of the click rubber member to abut the base plate, whereby the angle of inclination of the operating member is restricted, thereby preventing two or more pairs of switching elements from being simultaneously brought into the ON state.
Further, as disclosed in Japanese Utility-Model Laid-Open No. 59-33640, there has been proposed a multi-way flipping switch, in which a protrusion protruding upwards beyond a housing is provided on an operating member, and in which a cross guide groove to be engaged with this protrusion is provided in the housing. In this multi-way flipping switch, the direction of inclination of the operating member is restricted to four directions by the above-mentioned guide groove, so that it is possible to prevent two or more pairs of switch elements from being simultaneously brought to the ON state.
In the multi-way flipping switch disclosed in Japanese Utility-Model Laid-Open No. 59-188644, in which the operating member and the driving member are held in the neutral state by using a spring, has a problem in that, when the resilient force of the spring for restoring the operating member from the inclined to the neutral state is set at a high level so as to reliably achieve the neutral state, the click feel generated in the hollow protrusion of the click rubber member is reduced by the resilient force of the spring, thereby impairing the operating feel (the click feel). The click feel might be enhanced by setting the resilient force of the spring at a low level. In that case, however, the restoring force for retaining the operating member and the driving member in the neutral state would become rather weak, resulting in the neutral state of the operating member becoming rather unstable. Further, when, after the buckling deformation of the above-mentioned hollow protrusion, the inclining force is further applied to the operating member, the driving member will reversely rotate on the buckled hollow protrusion, thereby eliminating the stop feel indicating the termination of the inclining operation. From this viewpoint also, this prior-art structure is subject to impairment of the operating feel.
In the multi-way flipping switch described in Japanese Utility Model Publication No. 3-23639, in which an inclined surface descending toward the center is formed on the surface of the top end portion of each hollow protrusion, whereby the movable contact can be reliably brought into contact with the stationary contact while being held in a parallel position to the stationary contact. However, such an asymmetrical hollow protrusion not only impairs the operating feel, but also complicates the molding process for the click rubber member, thereby leading to an increase in production cost. Further, in this prior-art structure, in which the protrusion provided on the operating member is brought into abutment with the hard base plate to thereby prevent two or more pairs of switching elements from being simultaneously turned on, has a problem in that a through-hole into which the protrusion is to be passed has to be provided in the click rubber member, placed on the base plate, so that there is the danger of some liquid, such as water or juice, intruding the base plate through this through-hole to thereby generate electrical trouble, etc.
In the multi-way flipping switch described in Japanese Utility Model Laid-Open No. 59-33640, in which the projection of the operating member moves along the guide groove of the housing when the operating member is inclined, has a problem in that, when, for example, the operating member is to be sequentially inclined in two different directions, it is necessary to first restore the operating member, after its inclination in one direction, to the neutral position before the operating member can be inclined in the other direction along the guide groove, so that a quick operation is not to be expected.